Check that your phone and carrier support Wi‑Fi Calling
Connect your phone to a Wi‑Fi network
Open your phone’s Settings
Turn on Wi‑Fi Calling
On iPhone, go to Settings > Phone > Wi‑Fi Calling
On Android, go to Settings > Network & Internet > Calls or Mobile Network > Wi‑Fi Calling
Follow any carrier prompts to activate the feature
Make sure Airplane Mode is off unless you want to use Wi‑Fi only
Dial the number as usual from the Phone app
Place the call and confirm it shows Wi‑Fi Calling
If it does not work, restart your phone and reconnect to Wi‑Fi